Issue the iptraf command with no parameters for menu-driven operation.
These options can also be supplied to the command:

-i iface - start the IP traffic monitor (use "-i all" for all interfaces)
-g - start the general interface statistics
-d iface - start the detailed statistics facility on an interface
-s iface - start the TCP and UDP monitor on an interface
-z iface - shows the packet size counts on an interface
-l iface - start the LAN station monitor ("-l all" for all LAN interfaces)
-B - run in background (use only with one of the above parameters)
-t timeout - when used with one of the above parameters, tells
the facility to run only for the specified number of
minutes (timeout)
-L logfile - specifies an alternate log file for any direct invocation
of a facility from the command line. The log is placed in
/var/log/iptraf if path is not specified.
-I interval - specifies the log interval for all facilities except the IP
traffic monitor. Value is in minutes.
-f - clear all locks and counters. Use with great caution.
Normally used to recover from an abnormal termination.